Ok, it seems that the process was done to get the rods all the same weight, which seems fair, but surely when you are talking about a complex shape like a con-rod, that is in a rotating mechanism, wouldn't you want to make sure that the weight at each end was equal for each rod, rather than just measuring the overall weight??

_________________Stu"Take one old performance car, modify it so that it is as good, if not better, than a new performance car"

mrbeige wrote:Ok, it seems that the process was done to get the rods all the same weight, which seems fair, but surely when you are talking about a complex shape like a con-rod, that is in a rotating mechanism, wouldn't you want to make sure that the weight at each end was equal for each rod, rather than just measuring the overall weight??

Yes,it is not just a case of making sure they weight the same.I discussed this a few weeks ago with the engineering firm that did all my work.Balanced means exactly that.Balanced.

I've never understood why peeps do this,what gain? i mean,ok if your dealing with a cast con-rod fair enough,you'd wanna get rid of the stressraiser/cast mark running down the center of the rod but as the G60 rods are forged steel i don't see the need.I've yet to come across a damaged/bent G60 rod,they are extremly strong buggers.Even after polishing the beam you'd still be left with the balancing 'pads' on the very top of the rod,another possible stress raiser when revvin' to 8000+rpm but i don't see PG rods gettin near that rpm level.Am i missing the point?.

Can't see the point in removing stress raisers but I can see the point in weight matching followed by dynamic balancing.

You are never going to get an exact match but by getting it closer you should ensure a smoother running engine which reduces parasitic loses through inbalance.

You really want to get the rods, pistons and crank balanced as a rotating assembly, so you need to provide the block too. This way it makes it easier for the folks doing the balancing to match up rods and pistons without having to remove a lot of material.

I had a guy called Steve Smith from Vibration free do my flywheel, rods, crank and pistons, wasn't huge money at £185 and most of that was for lightening the flywheel. I went over to his workshop a few times, really good bloke and he has lots of interesting stuff over there he is only too happy to talk about. Used to do BAR Hondas F1 wheel balancing so has to be pretty good!

You can lighten the rod that way without any strength issues as you are getting rid of surface weaknesses. In an ideal world in needs shotpeening afterwards for improved yield strength.What I can tell you from that picture is that the rods will need balancing end over end again as they will no longer be in balance. It doesn't take a lot of material removal to make them out by 1 gramm.